This looming decline is historically unprecedented, and has huge implications for the already-ailing U.S. economy.

Immigrant entrepreneurs have historically fueled the U.S. economy. Since the 1960s, especially, there has been an uptick in skilled immigrants coming to the United States for work—many of them consistently starting businesses about a decade after their arrival.

Wadhwa's latest research into these trends finds that, not only have the numbers of immigrants starting businesses in the United States plateaued, many are choosing to take their business ideas back to their home countries after a period in the United States (the oft-cited "reverse brain drain") or to remain at home due to improved business prospects in their own and other countries.

The United States can reverse these trends. As Wadhwa found, many skilled immigrants—if policy and opportunities changed slightly in their favor—would gladly remain in the United States.

He brings statistics to life by citing personal stories of high-ranking graduates and award-winning innovators stuck in unnecessary immigration limbo on their way to launching a business here, and he proposes seven straightforward changes (some counterintuitive and none at the cost of the taxpayer) that would stanch the immigrant exodus and drive significant economic growth for the U.S. economy.